Hey Akanksha

Don't feel like that, you being dumb. It is just that there is lack of practice and unclear concepts. To overcome this, first of all clear your concepts and theory from NCERT or reference book you prefer. Once you do it, start solving exercises given in the same book. Gradually when you do this, your base for that particular topic starts getting strong and then do HC Verma Objectives. Where in, read the theory, which is not much elaborated and remember your formulas and start solving the questions, if you get stuck, refer the solutions and do it by yourself. Doing this will definitely give you a better edge.

But remember, to make this technique effective you need to be consistent, you need to devote some amount of time on this everyday. And later, when you solve HC Verma, you can refer more preparatory books like DC Pandey and most importantly previous years, considering JEE/NEET.